Known is a sealed medical storage of mixing type for use in a intravenous dripping or dialyzing, which is of multi-solution-mixing type. Such a sealed medical storage of mixed type is formed as a bag made of a flexible film and having an inner space, which is divided into compartments by means of a weak sealed portion, which compartments are for separately storing different medical liquids. Arranged at an outer periphery of the bag is an outlet port made as a plastic molded product of a tubular shape. The outlet port has an inner passage, which is, at its first end, opened to one of the compartments and is, at its second end, provided with a plug made of a rubber material. Prior to an administration of the medical liquid to a patient, the medical bag is, at its outside, pressed in a manner that the weak sealed portion is broken. As a result, a single compartment is created in the medical bag, so that the two kind of the medical liquids are mixed with each other. Then, a piercing of the rubber plug by a needle of an infusion set connected to an infusion line is done, which allows an administration of the mixed medical liquid to be possible. In short, in such a sealed storage for medical liquid of mixing type for medical treatment, a step for opening the weak seal portion for mixing both of the liquids is essential prior to the commencement of an administration of the medical liquid. Contrary to this, a piercing of the rubber plug at the liquid outlet without breaking the weak seal portion may cause a wrong operation to be generated that the medical liquid only at the single compartment adjacent the liquid outlet is administered. As a prior art combating this problem, a solution is proposed, wherein, in addition to a first weak seal portion separating the inner cavity of a medical bag into two compartments, a second weak seal portion is provided at a location slightly upstream from the liquid outlet, wherein a pressure for opening the second weak seal is, in comparison with a value of a pressure for opening the first weak seal portion, such that the first weak seal portion is, first, opened and, then, the second weak seal portion is opened, thereby ensuring a discharge of the medical liquids after the completion of the liquid mixing operation. See patent document 1
Patent document 1:Unexamined Japanese PatentPublication No. 2004-662